How to Determine Whether Steel Fiber Dosage and Quality in UHPC Products Meet Requirements?

How to judge whether the steel fiber content and quality in UHPC products meet the requirements? As an industry leader with 28 years of full-chain experience in the UHPC/GRC/GRG/GRP materials field, Qinglong Group will provide a practical testing guide for designers, owners, and project parties from a professional perspective, helping to control the core quality of UHPC materials.

### I. Steel Fiber Content Testing: Controlling UHPC Mechanical Performance from the Source As the core reinforcement material for UHPC strength, steel fiber content directly affects the compressive and flexural performance of products. Professional testing can be performed using the "ignition method": take a quantitative UHPC sample, burn it at high temperature to remove the cement matrix, weigh the remaining steel fiber mass, and calculate whether its proportion meets design requirements (typically 1.5%-3%). Qinglong adopts an automated feeding system in production, ensuring that the steel fiber content error per cubic meter of UHPC is controlled within ±0.1%, while verifying compliance through third-party testing institutions in accordance with industry standards such as the "General Technical Conditions for Non-load-bearing Components of Ultra-High Performance Concrete (UHPC)" (Plan No. 2024-0232T-JC). For more industry information: +WeChat qlfsbl123

### II. Steel Fiber Quality Identification: Analysis of Three Key Indicators 1. **Fiber Morphology and Dimensions**: High-quality steel fibers should have a straight or hooked-end appearance, with a preferred length of 13-25mm, diameter of 0.2-0.4mm, and an aspect ratio controlled at 50-80. Microscopic examination can be used to check whether fibers show bending, rust, or breakage, ensuring uniform dispersion in concrete. 2. **Mechanical Performance Testing**: Tensile testing is used to check the tensile strength of steel fibers (must be ≥2800MPa) and elastic modulus, with elongation at break required to be ≥3%. Qinglong selects high-strength low-alloy steel fibers, and every batch passes tensile strength testing to ensure coordinated load-bearing with the cement matrix. 3. **Dispersion Verification**: Cut a cross-section of a UHPC test block to observe whether steel fibers are evenly distributed, avoiding clumping. Qinglong employs a high-speed vortex stirring process combined with a special dispersant to ensure three-dimensional random fiber distribution in the matrix, enhancing the material's crack resistance.

### III. Full-Chain Quality Control: Quality Assurance Backed by Qinglong's 28 Years of Experience As a national high-tech enterprise and participant in UHPC standard development, Qinglong has established a full-process quality control system from raw material screening to finished product acceptance: - **Source Control**: Strategic partnerships with renowned steel fiber suppliers, with factory inspection reports provided for each batch of materials to ensure stable fiber performance; - **Production Monitoring**: Intelligent metering systems and online image recognition technology for real-time monitoring of fiber content and dispersion status; - **Finished Product Testing**: In accordance with the "Ultra-High Performance Concrete (UHPC) Exterior Wall Panels" T/CBMF171-2022 standard, each batch of products is tested for flexural strength, elastic modulus, and other indicators; any products failing these tests are resolutely not released from the factory. For more industry information: +WeChat qlfsbl123

### IV. Customer Empowerment: Core Criteria for Choosing a Reliable UHPC Manufacturer For designers and owners, judging steel fiber quality requires more than laboratory testing—it also demands an assessment of the manufacturer's overall strength: - **Qualification Certifications**: Whether the company holds credentials such as national high-tech enterprise and specialized & sophisticated enterprise status, and whether it participates in industry standard development; - **Case Verification**: Whether the company has application experience in large landmark projects, such as supplying UHPC components for complex scenarios like commercial complexes and museums; - **Service Capability**: Whether full-chain services from detailed design to construction and installation can be provided—for example, Qinglong provides customers with BIM parametric design support and on-site installation guidance to ensure steel fiber performance is fully realized in projects.

The excellent performance of UHPC is inseparable from the quality assurance of steel fibers. Choosing a professional manufacturer like Qinglong, with 28 years of technical accumulation, can fundamentally avoid engineering risks caused by insufficient steel fiber content or quality issues. Qinglong always upholds the philosophy of "meticulousness and the pursuit of excellence," providing global customers with high-quality UHPC/GRC/GRG/GRP products to help create beautiful architecture.